A study by the University of Texas has found that men who drank two cups of coffee a day were 42 per cent less likely to suffer from erectile dysfunction compared to men who didn’t.

Scientists studied 4,000 men drinking caffeinated drinks including coffee, tea, fizzy and sports drinks and found the result was the same regardless of weight, age or blood pressure. The effect remained true regardless of whether men were overweight, obese or suffered from high blood pressure

Scientists believe it could be because the caffeine triggers a chemical reaction that increases blood flow to the penis by relaxing muscles.

But two cups might be the limit as the researchers also found the result dipped slightly to 39 per cent for men drinking three a day.

Previous research has already suggested the caffeine can boost sex drive in women.

In a 2006 experiment on female rats by Southwestern University in Texas, scientists found drinking coffee stimulated the parts of the brain that signal sexual arousal. But this effect could possibly be seen only in women who did not drink coffee regularly.

Scientists have long argued whether too much coffee is bad for you with some argue drinking more than four cups a day is dangerous as it causes restlessness, tremors, and irritability, insomnia and stomach pain.